* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

/*flex布局*/
.flex_dom {
  display: flex;
}

.flex_column {
  display: flex;
  flex-direction: column;
}

.flex_1 {
  flex: 1;
}

.flex_2 {
  flex: 2;
}

.flex_3 {
  flex: 3;
}

.flex_4 {
  flex: 4;
}

.flex_5 {
  flex: 5;
}

.flex_justify_between {
  justify-content: space-between;
}

.flex_justify_around {
  justify-content: space-around;
}

.flex_justify_center {
  justify-content: center;
}

.flex_align_center {
  align-items: center;
}

.flex_align_stretch {
  align-items: stretch;
}

.flex_wrap {
  flex-wrap: wrap;
}

/* 文本 */
.text_left {
  text-align: left;
}

.text_center {
  text-align: center;
}

.text_right {
  text-align: right;
}

.line_text_1 {
  overflow: hidden;
  display: -webkit-box;
  line-clamp: 1;
  box-orient: vertical;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 1;
}

.line_text_2 {
  overflow: hidden;
  display: -webkit-box;
  line-clamp: 2;
  box-orient: vertical;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.line_text_3 {
  overflow: hidden;
  display: -webkit-box;
  line-clamp: 3;
  box-orient: vertical;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

/* 居中 */
.margin_center {
  margin-left: 50%;
  transform: translate(-50%);
}

.position_center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

/* 禁止选中文本 */
.usn {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  -o-user-select: none;
  user-select: none;
}

/* 定位方式 */
.ps {
  position: static;
}

.pr {
  position: relative;
}

.pa {
  position: absolute;
}

.pf {
  position: fixed;
}

/* 浮动 */
.fl {
  float: left;
}

.fr {
  float: right;
}

/* 清除浮动 */
.clearfix {
  zoom: 1;
}

/* 强制不换行 */
.wn {
  word-wrap: normal;
  white-space: nowrap;
}

/* 强制换行 */
.wb {
  white-space: normal;
  word-wrap: break-word;
  word-break: break-all;
}

/* 元素类型 */
.db {
  display: block;
}

.dn {
  display: none;
}

.di {
  display: inline;
}

.dib {
  display: inline-block;
}
